Reviewing Calculations involving Ratios

Introduction to Ratios




(i) Ratios and Lowest Terms




(ii) Solving Ratio Problems: Using Cross Multiplication




(iii) Solving Ratio Problems : Part to Part and Part to Whole Ratios




(iv) Scale Drawings




Similar Triangles

(i) Naming and using the corresponding sides and angles in similar triangles





(ii) Calculation of unknown sides and angles using similar triangles
(remember: if two triangles are similar, then they have the same angles AND their sides are 'proportional'
the sides are 'proportional' means that you can multiply the sides by a single number to get
the sides of the other triangle - this single number is called the scale factor )


a. Similar Triangles powerpoint presentation from class (many examples)



b. More sample calculations





c. Good explanation of similar triangles (ignore the SAS and RHS conditions - we only did SSS and AAA)





c. How to determine the scale factor - several examples



d. More Examples







Trigonometry







Nice explanation of 'SOH CAH TOA' and nice sample calculations




Another Lesson explaining the Trigonometric Ratios sine, cosine and tangent



Still Another Explanation with examples




Overview of the Ratios and an example of finding an unknown angle




Example of 'Solving' a Triangle